There is different factors to find how much to charge. How much do you want to make a hour and how long do you think the job will take and the materials you will use = $ you will change. What does your competitors charge, how much experience do you have on detailing and figure out a good trade.
Different parts of the U.S. has different economics like southern Calif may charge $65 hr for a carpenter while back east a carpenter could make $20.00 hr